Compressor bleed valves may be found on gas turbine engines powering commercial and military aircraft. At certain stages of the engine operation, the valves bleed high-pressure air from the compressor into the fan duct. The resulting process generates noise that may dominate over other sources of engine noise. Thus, particularly on approach when the engine is throttled back, the noise generated from the valves becomes a significant factor of overall aircraft noise. Bleed valves are typically installed on the high-pressure and intermediate-pressure sections of the compressor, hence the naming High Pressure Bleed Valve (HPBV) and Intermediate Pressure Bleed Valve (IPBV).
Current techniques to suppress noise from bleed valves in gas turbine engines have a number of drawbacks. These existing techniques involve a muffler with one or more stages of perforated plates. The stages of perforated plates in these designs have rendered the resulting design to be bulky and heavy which penalizes engine performance. In addition, adding many suppression stages reduces the mass flow rate such that the valve design is required to be larger which again gives rise to weight issues.